ConchoidalArthur Thomas, Gemstones (2009), ConchoidalArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Conchoidal, Uneven, ConchoidalWalter Schumann, Gemstones of the world (2001) More from other references, Brittle
MgAlBO 4Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references
FeS 2Michael OâDonoghue , Gems, Sixth Edition (2006) More from other references